Re: data manipulation for plot

[verschel@xxxxxxxxxxxxxxxxxxxxx (Mark A. Verschell)]

Very simple, Kerry.

All you have to do is define a new variable that has a value when the spd is
high enough, and is undefined when the spd is less than the chosen value.

E.g.:
yes? LET minspd = 2.0
yes? LET gdir = IF spd gt minspd THEN dir
yes? CONTOUR gdir

The IF statement is the key. By not including an ELSE statement in the
definition, the value of gdir is implicitely undefined whenever the if test
fails. Of course, you don't need the two LET statements, they could be made
into one {IF spd gt 2.0 THEN dir}, but I find this format more
self-documenting.

Mark

On Jun 12,  2:27pm, kerry.wo@hk.mw.com wrote:
> I have adcp data in spd and dir at one location over water column and
> time and I would like to plot a contour dir over time and depth only
> when its corresponding spd is greater than a particular value.
>
> How could I manipulate the data for the plot or how could I let those
> dir to be a missing value when its corresponding spd is greater than a
> value specified?


-- 
 Mark Verschell                     NASA/Goddard Space Flight Center
 verschell@neptune.gsfc.nasa.gov    Code 970/Lab. for Hydrospheric Proc.
 301-286-2027  Fax: 301-286-1761    Greenbelt, MD 20771